1. Field of the Invention
This invention relates to a timepiece of the type and size that one would carry on their person such as a wristwatch or a pocketwatch. The timepiece has a single casing which contains the timing mechanism, inner workings of a clock and interchangeable cartridges that contain the time indicating devices such as clock hands and a clock face. The cartridge can be snapped into or out of the casing easily. A cartridge snapped into a casing forms a unitary timepiece.
2. Description of the Prior Art
With respect to the prior art, the following U.S. patents are known: U.S. Pat. Nos. 4,525,077; 4,253,178; 1,469,735; 1,591,512 and 2,603,924.
U.S. Pat. No. 4,525,077 discloses a timepiece such as a pocket or a wristwatch having a large central opening through the watch center causing the watch to assume a toroidal configuration. The entire time mechanism and time display indication devices are contained within the toroidal configuration and the central opening formed is for the purpose of receiving interchangable decorative inserts which fit inside the central opening. The decorative inserts, however, do not perform any time keeping or time indicating functions, as all such mechanisms for performing these time functions are contained in and displayed on the surrounding timepiece.
Similar in nature is U.S. Pat. No. 1,591,512 where there is a watch case having ornamental plates which are removably mounted around the timepiece. The wearer of the watch changes the decor of the watch by interchanging the ornamental plates. Again the plates' only functions are decorative and have no relation or connection to the actual time indication function of the watch.
Also known and disclosed in the prior art are decorative mountings for timepieces as in U.S. Pat. No. 2,603,942 which discloses a single timepiece unit mounted inside an ornamental holder. The holder contains a means to mount the timepiece, but again, the purpose is strictly ornamental. Similarly, U.S. Pat. No. 4,253,178 discloses an ornamental device which is a removable/attachable device for a watch or timepiece.
Finally, U.S. Pat. No. 1,469,735 discloses an item which is useful for a pocket watch style timepiece where a decorative filler ring is placed inside the pocket watch casing so that it may accommodate timepieces of different sizes.
None of the above patents, teach the objectives of the present invention, that is to provide a single time mechanism which operates interchangeable time indicator cartridges. The cartridges may include ornamental design, but can be limited to strictly functional purposes. The known prior art merely provides a means for changing ornamental decor which has no relation to the time keeping function of the watch.